Because of the close tie between the PHL core laboratory functions and the disease surveillance and epidemiology functions of the CDC, the greatest potential for collaboration between PHLs and the federal government lies within the CDC. The PHL relationship with the CDC is robust, and one that is important for national disease surveillance.
The Division of Laboratory Systems (DLS) within the Public Health Practice Program Office (PHPPO) at CDC plays an important role in clinical laboratory issues at the CDC. With 90 FTEs -- laboratory scientists, statisticians, computer specialists, physicians, and administrative support personnel --DLS performs many functions on laboratory-related issues and coordinates many laboratory-related activities within the agency (see Figure 7). For example, DLS officials are represented on a newly formed working group on public health laboratory issues at CDC that serves on an advisory committee to the director of the agency. Other centers at CDC such as the National Center for Infectious Diseases (NCID) are also integrally involved in lab activities (see Figure 7).
|Figure 7: Coordination of Laboratory Activity between CDC Centers and Division of Laboratory Systems|
|Name of CDC Center/Office||Lab-Related Functions||Relationship with DLS/Current Activities|
|Office of the Director||N/A||There is an advisory panel to the Director of CDC on issues concerning public health labs. Representatives from all CDC Centers, including the Director of PHPPO.|
|Office of Managed Care||N/A||This office is still assessing its role in regard to public health labs. A representative from DLS acts as an advisor on public health labs to the Office of Managed Care.|
|National Center for Infectious Diseases (NCID)||Conducts lab and epidemiologic research for prevention of emerging diseases (lab-based surveillance)
Collects, analyzes, and interprets reports of nationally notifiable infectious diseases and outbreaks submitted by state/local agencies
|This center has the directive to write guidelines for diagnosing infectious diseases and consults with DLS on laboratory testing included in those guidelines. In addition, as part of the DLS responsibility for writing and implementing regulatory standards for the Clinical Laboratory Improvement Act, DLS staff consult the NCID on regulations for infectious disease testing.|
|National Center for Environmental Health (NCEH)||Develops lab measurements of exposure to toxicants
Conducts lab assessment of exposure and disease for health studies of toxicants (lead, mercury, dioxin, pesticides)
Provides lab support during environmental health emergencies
Provides technical assistance, training, and technology transfer to states
|NCEH runs a blood lead program, and consulted DLS on the emergence of new hand-held technologies for field testing of blood lead.|
|Epidemiology Program Office (EPO)||Publishes MMWR
Coordinates CDC Surveillance Efforts (collects/analyzes data, sends out epidemiologists during outbreaks)
Operates a surveillance telecommunication system between CDC and all 50 states
|This link is not as close as might be expected. EPO consults DLS when the issue concerns the actual management and running of the laboratories.|
|National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP)||N/A||This center works jointly with DLS on implementation of the Fertility Clinic Success Rate and Certification Act of 1992. Specifically, DLS is developing and publishing the model certification program, mandated in the law, for embryo laboratories.|
In terms of the types of relationships that have emerged between CDC and PHLs, the CDC's roles in laboratory issues have included: a) laboratory regulation; b) training of PHL personnel; c) disease surveillance; and d) other activities supporting PHLs.
Among DLS's most central responsibilities is implementing and authoring, with HCFA(now known as CMS), the Clinical Laboratory Improvement Amendment (CLIA) regulations. Congress passed CLIA in 1988 to establish baseline quality standards for all clinical laboratories in the United States. HCFA(now known as CMS) has the responsibility for registering laboratories and collecting fees, while CDC has responsibility for technical and scientific issues related to the regulation, such as test categorization, decisions on waivers, and evaluating the impact of the regulations on the public. HCFA(now known as CMS) and CDC share responsibility for authoring and refining the regulatory standards.
Training of PHL Personnel
DLS sponsors symposia on best practices in laboratory operations. In 1995, DLS sponsored The Institute on Critical Issues in Health Laboratory Practice. The Institute brought together presentations and discussions on different areas of laboratory practice research:7
- proficiency testing
- laboratory personnel
- quality assurance
- detection of problems affecting patient outcomes
- establishment of analytical performance goals for the laboratory
- measurement of the impact of change on laboratory testing
- laboratory-focused health systems research
In addition, DLS also has cooperative agreements with ASTPHLD to conduct laboratory training courses on clinical, environmental, and public health laboratory topics. The National Laboratory Training Network (NLTN), a joint venture of ASTPHLD and DLS, provides laboratory training courses in clinical, environmental, and public health topics to laboratory personnel.
While exhaustive characterization of CDC disease surveillance activities is beyond the scope of this study, it is important to describe briefly the interplay between PHLs and the CDC on this issue. As the national health agency responsible for disease surveillance / epidemiology and disease prevention, the CDC's mission complements those of the PHLs.
PHLs play a critical role in national disease surveillance; the emergence of new infectious agents and the re-emergence of infectious disease threats are focusing attention on the need for a strong public health laboratory infrastructure.8 PHLs, along with other providers, report the occurrence of notifiable diseases to state and local health agencies. Requirements for reporting diseases are mandated by state laws or regulations, and reportable diseases vary by state.
The data generated by PHLs are necessary for monitoring disease trends and evaluating the effectiveness of public health interventions. More specifically, data on a number of infectious diseases are aggregated into a national database at the CDC called the National Notifiable Diseases Surveillance System (NNDSS). A list of diseases included in the NNDSS is provided below in Figure 8. The national data from the NNDSS are published weekly in the CDC's Morbidity and Mortality Weekly Report (MMWR). In addition to the NNDSS, other conditions of public health interest are provided by state health departments to the CDC through supplementary surveillance systems.9
|Figure 8: Diseases in the National Notifiable Diseases Surveillance System (NNDSS)|
|Source: CDC Case Definitions for Public Health Surveillance. MMWR 39(RR-13), October 19, 1990.|
Congenital rubella syndrome
|Hepatitis A, B, non-A or B
Rocky Mountain spotted fever
Toxic shock syndrome
The interchange among providers, PHLs, state health agencies , and the CDC is illustrated in the example of the surveillance system for antimicrobial-resistant pneumococci. Figure 9 below shows an idealized flow of information through a computerized, laboratory-based surveillance system. The physician sends the patient's pneumococcal isolate to the PHL, which then performs susceptibility testing to determine the level of resistance of the isolate to various antibiotics. The susceptibility data are recorded electronically into the laboratory's database, which then transmits this information to the state health agency via an HL7 message. The state health agency communicates the local trends for pneumococci back to the physician and to the CDC. Finally, the CDC communicates the national trends on antibiotic resistance of pneumococci back to the state, physician, and public health community.10 Efforts to develop such a system are actively being pursued through a collaboration involving the CDC, Council of State and Territorial Epidemiologists (CSTE), and ASTPHLD.
Figure 9: Idealized Information Flow in Electronic Disease Surveillance System
Source: MMWR, February 16, 1996, p. 8
The CDC is also involved in helping state PHLs respond to disease epidemics and outbreaks. For example, during the 1994 Hantavirus Outbreak in the Four Corners region of the Southwest United States, CDC epidemiologists provided technical expertise in helping the state health agencies determine the cause of the outbreak. In general, the CDC provides as much assistance as the state health agencies request, which can range considerably. For example, during the recent E. coli outbreak in apple juice from California and Washington State, CDC involvement was minimal, while the FDA played a substantial role.
In addition to the aforementioned functions, the CDC provides other ancillary support services for PHLs. For example, DLS often serves as a source of technical support for PHLs. In limited instances, the CDC funds PHL programs through grants. For example, the CDC's National Center for Infectious Diseases (NCID) recently provided a grant to the Washington State PHL and Office of Epidemiology to create an innovative system for electronic disease reporting in hopes of lessening the burden of reporting, improving accuracy, and expediting reporting.